1. Technical Field
The present invention relates to a backlight module structure, and more particularly, to an LED backlight module structure for increasing process yield.
2. Description of Related Art
Light-emitting diodes (LEDs) are the widely used light-emitting devices. The LED has the advantages of small volume and lone lifetime, so that it is widely used in human life.
Recently, LEDs are also applied in backlight module. Please refer to FIG. 1, which illustrates a stereo diagram of a conventional LED backlight module. As shown in FIG. 1, the conventional LED backlight module 1′ includes: a housing 11′, a copper circuit layer 12′, a plurality of LED chips 13′, a reflector 14, a light guide plate 15, and a bottom reflector 16′, wherein the housing 11′ includes a housing bottom 111′, and the copper circuit layer 12′ is disposed on the hosuing bottom 111′ through a thermally conductive insulating layer. Please refer to FIG. 2, there is shown a stereo diagram of the LED chip. As shown in FIG. 2, a plurality of welding pins are exposed out of the package 130′ of the LED chip 13′, including positive welding pins 131′ and negative welding pins 132′; and LED chip 13′ has a light-emitting surface 134′ in the top thereof.
Referring to FIG. 2 again, and please simultaneously refer to FIG. 3A, FIG. 3B and FIG. 3C, there are shown schematic welding processes diagram of the LED chips. As shown in FIG. 3A, when executing the welding process of the LED chips 13′, an LED carrier 3′ is general used for carrying the LED chips 13′ and putting the LED chips 13′ on the surface of the copper circuit layer 12′, and then, as shown in FIG. 3B, the positive welding pins 131′ and the negative welding pins 132′ contact with the welding points 122′ of the copper circuit layer 12′, wherein the solder is disposed on the welding points 122′ in advance. Continuously, as shown in FIG. 3C, a pressing fixture 2′ is used for pressing the LED chips 13′, and then the housing 11′ is heat for melting the solder on the welding points 122′, so as to weld the positive welding pins 131′ and the negative welding pins 132′ on the welding points 122′.
The aforesaid LED backlight module 1′ is widely used in liquid crystal display, in addition, the pressing fixture 2′ levels all the LED chips 13′ on the copper circuit layer 12′ when the welding process is executed, such that the backlight quality of the LED backlight module 1′ is good. Even so, the LED backlight module 1′ still includes the drawbacks and the shortcomings as follows:                1. When executing the welding process of the LED chips 13′, the solder paste overflow phenomenon may occur between the bottoms of the LED chips 13′ and the copper circuit layer 12′, and cause the positive welding pins 131′ electrically connect to the negative welding pins 132′, such that some LED chips 13′ may fail to normally work.        2. Inheriting to above point 1, furthermore, the solder paste overflow phenomenon may directly influence the process yield of the LED backlight module 1′.        
Accordingly, in view of the conventional LED backlight module still has shortcomings and drawbacks, the inventor of the present application has made great efforts to make inventive research thereon and eventually provided an LED backlight module structure for increasing process yield.